Cannot View All Files In Shared Folder

I am running winows 7 ultimate 32bit as a server, i have the c: drive shared to all 13 users on the network. All 13 computers are running windows xp pro. The problem that I am having is this:When i open up the shared c: drive on a windows xp computer, and open a folder to view files, it only shows 122 out of the 227 files.when i open up the c: drive on the windwos 7 machine, i can see all 227 files.when i open up excel or word, and open a file that is stored on the windows 7 machine, it will open fine, but when i try and browse for the file that is stored on the windows 7 machine, it does not show it.now here is the interesting thing:when i open up the shared c: drive on another computer running windows 7, (not the server) i can see all 227 files and have no problems.i have multiple folders, ex: mypics2008, mypics2009, mypics2010, mypics2001, mydocs2000, mydocs2010, all shared off of the c: drive on the windows 7 server. this problem started a few weeks ago, i was able to see all the files in every shared folder off of the windows 7 server through all of the windows xp pr machines a month ago, and all of a sudden in the past few weeks, i am no longer able to see all of the files shared off of the server.i have rebuilt the index on the windows 7 server i have removed and redone ALL security, and sharing settings i have checked, rechecked and checked again all the file sharing settings I am stumped, and i consider myself knowledgable with computers.